Portable polishing machine



Sheets-Sheet l H. J. PATTISON ET AL PORTABLE POLISHING MACHINE Filed Feb. 19, 1936 B Y M,

Jan. 25, 1938.

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Jan. 25, 1938.

H. J. PATTISON ET AL PORTABLE POLISHING MACHfNE Filed Feb. 19', 1956 72 Sheets-Sheet 2 ATTORN EYS.

Patented Jan. 25, 1938 PORTABLE rousnme MACHINE Herbert J. Pattison, Detroit, and William K. Barton, Grosse Pointe Park, Mich, assignors to Briggs Manufacturing Company, Detroit, Mich, a corporation of Michigan Application February 19, 1936, Serial No. 64,608 1 Claims. (e1. 51-110) The present invention relates generally to machines having a moving belt preferably-used to polish fiat or curved surfaces and, more particularly, to portable polishing machines for polishing the enamel, lacquer, or other finish of automobile bodies.

The portable polishing machines which have hitherto been commercially available have been either of the reciprocating pad type, the rotating disc type, or the rotating cylinder type. The first .of these three types is slow because of the starting and stopping of the pads at the end of each stroke, the second type is slow because only a small sector of the disc pad can be effectively held against the surface to be polished and because only a shall zone on the disc is moving at theoptimum speed, and the third type is slow'because only a narrow element of the cylinder is in contact with the surface to be polished. One of the from the above objections, which will polish a comparatively large area at once and in which all parts of the polishing member move at the same optimum speed.

Another object of this invention is to provide a portable polisher with means to collect and dispose of the dust created by the polishing operation.

Another object of this invention is to provide a portable polisher of the belt type with means to keep the belt under constant tension-and permitting its easy removal and replacement.

Another object of this invention is to provide a portable polisher of the belt type with simple means to keep the belt in position.

Other objects and advantages of the invention will appear from the following description and appended claims when considered in connec- 40 tion with the accompanying drawings forming a part of this specification.-

Fig. l is a side elevation of one of the preferred embodiments of the invention with many of the parts broken away to the central vertical plane and shown in section. I

Fig. 2 is a sectional view on the line 2 2 of Fig. 1, taken in the-direction of the arrows.

Fig. 3 is a sectional view on the line 33 of Fig. 1, taken in the direction of the arrows.

50 Fig. 4 is a sectional view on the line 4 4 of Fig.

1, taken in the direction of the arrows.

Before explaining in detailthe present invention it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in principal objects of this invention is to provide a the accompanying drawingasince the invention is capable of other embodiments and of being prac ticed or carried out in various ways. Also it is'to be understood that the phraseolo'gy or terminology employed herein is for the purpose of descrip tion and not of limitation, and it is not intended to limit the invention claimed herein beyond the requirements of the prior art.

The particular embodiment of the invention shown in the drawings comprises a polishing belt to stretched over two pulleys ll, l2, 'an electric motor l3 above the belt ill with its shaft l4 parallel to the run of the belt, a fan l5 mounted on the motor shaft l4 and arranged to draw in the dust created-by the polishenand gearing extending from the end of the motor shaft around the edge of the belt and driving one of thepulleys. These and the other parts which form the polisher are mounted in or upon a frame or body l6 which extends lengthwise of the polisher between the motor l3 and the belt l0 and downat one side of the belt l0 and which has a forward portion extending up in front of..the motor I3 and down i front of and atthe side of the belt l0. 1 The portion lfia of the frame I6 at the side of the belt lllcarries the pulleys ll, l2, 11 which support and guide the belt. The drive pulley II at the front end is mounted on a shaft 18 carried by a ball bearing IS in a boss l6b projecting in between the two sides of the belt I0 from the side Ilia of the frame. The other end of the belt l0is carried by an idler pulley l2 running on a pair'of ball bearings 20 and 2! on a shaft'22 carried by a yoke 23 which lies within the-belt Ill. The yoke 23 is carried by a pair of cylinders 24 riveted to it and slidably mounted in a pair of parallel holes 25 in a guide block 160. The guide-block I6c' proders 24 are formed into racks 24a which are engaged by a gear-like splined shaft 21 rotatably mounted in a transverse hole in the guide block and retained by a pin 28 fitting into a circumferential groove on the shaft. The splined shaft 21 is providedwith a lever 21a, by which it may be rotated, and an arm 21b, which carries a small spring pressed plunger 29 adapted to snap into a bushed hole 30 in the side of the guide block I60 Hi alongside of the belt 13,

when the lever 21a is swung down into vertical position. The teeth on. the shaft 21 and on the cylinder 24 are engaged so that when the cylinders 24 and the yoke 23 and idler l2 carried by them are in their normal position with the belt l3 tight, the handle 21a on the shaft lies horizontally out of the way along the side of the machine. Then when the handle 21a is swung down and the plunger 23 snaps into the hole 33 in the guide block I30, theidler |2 will be retracted enough to allow easy removal and replacement of the belt l3.

The belt I3 is kept centered upon the pulleys II and I2 by the guide pulley l1 which lies between the drive pulley II and the guide block |3c for the idler pulley yoke cylinders 24. The guide pulley "turns on a pair of ball bearings 3| and 32 mounted upon a stud 33 screwed into a boss |3d on theside |3a of the frame or body and it engages the bottom of the upper run of the belt III. A pair of end plates 34 and 33 screwed onto the sides of the guide pulley l1, form flanges engaging the edges of the belt I 3 and do the actual guiding. Removal of the belt over the edge of the flange 34 is facilitated by a hollow 33 in the frame just above the pulley flange 34 on the open side of the machine.

It is important to note that the lower or working portion of the belt l3 may be pressed upward for a certain distance and, therefore, the belt 13 may be conveniently applied to surfaces curved longitudinally or transversely of the belt, such for instance, as a rounded corner of an automobile body, and to engage such surface by the major portion of its working area. It should be also noted, that such inward pressure applied to the belt |3 draws the pulleys II and I2 against the spring 23, thus increasing the tension forces acting on said belt l3, thereby also increasing the total normal pressure exerted by said belt on the polished surface. Considering the fact that being so pressed, the belt l3 follows the curvature of the surface and that the area of contact of the belt and the polished surface is usually increased when the belt is pressed up, it will be appreciated I versely of the belt, and thereby to equalize the normal pressure of the belt on the polished surface at different points of contact; and, second, to resist with a greater force the transversely directed reaction of the polished surface, tending to throw the belt ofi the pulleys II and I2, when the axes of the pulleys are not parallel to the line tangent to such curved surface.

The drive of the belt I3 is from the motor shaft |4 through a pair of bevel gears 31 and 33, a cross shaft 33 and down the side of the frame or body l3 through a train of spur gears 43, 4| and '42 to the shaft |3 which carries the drive pulley The gears 43, 4| and 42 are enclosed in a housing formed by a recess in the side of the forward part of the body l3 and by a gear cover 43 fitting over the recess and supporting the outer ends of the shafts 33, 44 and I 3 upon which the gears 43, 4| and 42 are mounted.

The lower gear 42 is keyed to the drive pulley shaft l3, the center of the shaft being supported by the ball bearing |3 in the boss |3b projecting into the end of the pulley II and the outer or gear end of the shaft |3 being supported by a ball bearing 43 mounted in the gear cover 43. The

drive pulley shaft I3 is located endwise by the ball bearing 1 3 supporting the center of the shaft, the inner race of the bearing |3 being clamped between the hub of the drive pulley II and a spacer 43 pressed on to the shaft 3 and the outer race being clamped in the supporting boss I317.

The central or idler gear 4| is freely rotatable on a ball bearing 41 carried by ashort shaft.

whose ends fit into recesses in the side of the frame or body l3 and in the gear cover 43.

The upper gear 43 is keyed onto the hollow transverse shaft 33 which is carried by anouter ball bearing 43 mounted in the gear cover 43 and in a central ball bearing 43 mounted in the frame.

'The inner end of the upper shaft 33 is integral with the bevel gear 33, whose back-is provided with a shoulder against which a nut 33 clamps the inner race of the central bearing 43. The outer race of the central bearing 43 fits up against a shoulder in the body. l3 facing towards the bevel gear 33 so as to take the thrust and, in addition, is held in place by a set screw 3|.

The bevel gear 33 formed integrally with the upper transverse shaft 33 is engaged by a second bevel gear 31 keyed onto the front end of the motor shaft l4, the two gears 31 and 33 being enclosed in a chamber |3e extending across the upper part of the body. The hub of the bevel gear 31 on the motor shaft I4 is carried by a ball bearing 32 mounted in a hollow boss l3! on the body projecting a short distance along the motor shaft H. The inner race of the bearing 32 is clamped between a shoulder on the bevel gear 31 and the hub 33 of the fan |3 on the motor shaft, the fan hub 33 bearing against a shoulder on the shaft I4 and projecting intothe bearing boss l3). The outer race of the bearing 32 is clamped between a shoulder in the bearing boss |3f and nut 33. The motor shaft l4 and bevel gear 31 are thus accurately positioned axially.

The fan 3 which serves to collect the dust created by the machine is of the centrifugal type and rotates in an involute housing |,3g formed integral with the frame or body |3 of the machine.

The front i3h' of the frame which extends down in front of the belt drive pulley II is hollow and forms an air duct 33 whose opening or nozzle is just in front of and above the lower run of the belt l0. A rubber apron or shield 31, fastened to the nozzle l3h; extends down in front and at the sides of the nozzle to intercept the dust thrown off by the belt and to prevent clean air from in by the fan. From the nozzle, the air duct 33 extends up and back under the bevel gear housing |3e to the center of the fan |3, the end of the duct extending up and encircling the front motor shaft bearing boss |3f which projects back from the bevel gear housing |3 e. A short vertical strut |3i extendsacross the duct 33 from the part of the frame I3 just above the belt l3 to the bearing boss l3} but, being in line with the flow of air, does not obstruct its passage.

The discharge conduit from the fan lies behind the housing for the vertical gear train and is formed into a rearwardly directed elbow Iii. A sheet metal discharge tube 33 whoseforward end fits into the end of the elbow I31 extends along front of the machine from being uselessly drawn the side |3a of .theframe to the end of the ma-.

' on one side to'allow the handle 21a, which retract-s the belt idler pulley II, to swing up past' it, as the belt stretches in service and lets the aromas chine where a flexible hose for carrying away the dust laden air can-be connected to it. The central part of the discharge tube 58 is flattened yoke 23 carrying the idler l2 move out beyond its normal position.

The rear of the fan chamber is closed by a partition 01" diaphragm 59 whose rim is bolted between the front end of the motor housing 8d and the back of the fan housing l6g. The center of the partition 59 is provided with a seal 69 which bears against a spacer 62 on the motor shaft between the dust removal fan hub 53' on one side of the partition 58 and a motor cooling fan 63 on the other.

The rear end of the motor shaft I4 is carried by a ball bearing 64 in a hollow boss 60a at the rear end of the motor housing 66. The rear end of the housing 60 in turn is secured in a saddle l6k at-the rear end of the frame or body I by means of screws 66. The actual motor 53 is a high speed heavy duty universal motor of the type used in electric drills. and, being conventional, is not illustrated in detail.

Each end of the machine is provided with a handle, the front handle 66 being screwed onto the front end of the frame 15 and the rear handle 61 being screwed onto the rar ends of the frame is and the motor housing 60. The wire 58 through which power is supplied to the machine enters the lower part of the rear handle 51 through a. conventional tapered rubber sleeve 69 and is connected to a standard switch 10 located in the upper part of the handle 61 and operated by a trigger H.

All of the bearings I9, 20, 2|, 3!, 32, 45, 41, 48, 89, 52 and 64 in the machine and the train of gears 3'|, 38, 40, ll and 42 are packed in grease. The grease for the gear train and its bearings is prevented from escaping by a seal 12 within the front motor bearing retainer 55 bear- .ing on the dust fan hub 53 and by' a leather washer 73 bearing upon the hub of the drive pulley H. The bearings 20, 2|, 3i and 32 of the idler pulley l2 and the guide pulley l1 and the rear motor bearing 64 are of the type known commercially as Greaseal" and are equipped ivith built in grease retainers, and the rear motor bearing 64 is provided in addition with a leather seal 14. Standard pressure grease gun fittings 15 are provided for' greasing all the bearings and gears, the fitting of the rear motor bearing 54 being on the side of the motor housing 60 and the others being as shown.

The machine is provided with a ball bearing supporting ring comprising an inner race 16 encircling the motor housing 60 and secured to it by set screws through lugs 15a on the side of the race and an outer race TI rotatable around the inner one 16 on steel balls 18 and provided with a ring or eye 11a. When the machine is in use, the eye "a is fastened to a hook or shackle on "the end of a line depending from a pneumatic balancer exerting a constant upward pull on the line and carrying the entire weight of the machine.

' other suitable belt is provided, waxing can be done with it. If a sandpaper or other abrasive belt is employed, smoothening of rough surfaces can be done. With the proper grade of abrasive and a belt provided with a felt or other suitable surface, the machine lends itself to rubbing down lacquer, enamel, varnish; paint, etc.

We claim:

1.- A portable polishing machine comprising a frame, a pulley carried by the frame, a guide block carried. by the frame and provided with a pair of parallel holes directed away from'the pulley and a transverse hole offset from but intersecting the parallel holes, a. pair ofcylinders slidable in the parallel holes and having gear teeth spaced along their length, a gear-like cylinder rotatable in the transverse hole with its teeth engaging the teeth on the slidable cylinders, manually operable means for rotating the rotatable cylinder, an idler pulley carried by the slidable cylinders, a polishing belt'around the pulleys, and resilient meansurging the slidable cylinders and the idler pulley away from the other pulley. n 2. A portable polishing machine as described in in the preceding claim 1, in which the slidable cylinders are hollow and in which the resilient means comprise helical .springs extending within the hollow cylinders.

3. A portable polishing machine comprising a longitudinally extending movable polishing element, a motor extending longitudinally above the polishing element, means for driving the polishing element from the motor, a ring freely rotatable about the motor, and means secured to the ring for supporting the machine.

4. In a portable motor driven tool, a motor having an elongated housing, a bearing member encircling the motor housing and movable longitudinally thereof, means for securing the bearing member to the housing at selected points along the length of the housing, a member carried by the bearing member and rotatable around the housing, and means on the last mentioned member for attaching a means for supporting the weight of the tool. I

'5. In a. portable polishing machine, a stationary rotatable pulley, a movable rotatable. pulley,

means for rotating said stationary pulley, an endless belt travelling over said pulleys, a stationary guiding block'between said pulleys having a bore, a plunger having one end thereof slidable in said bore and its opposite end carrying the movable pulley, a spring arranged in said bore and urging the movable pulley away from the stationary pulley, a gear and rack means. for moving the movable pulley through a predetermined distance, and means positively locking said plunger at the extreme points of said distance.

6. In a portable polishing machine, a stationary rotatable pulley, a movable 'rotatable pulley,

means for rotating said stationary pulley, an endless belt over said pulleys, a stationary guiding block between said pulleys having a bore, a. plunger having one end thereof slidable in said bore and its opposite end carrying the movable pulley, a spring arranged in said bore and urging the movable pulley away from the stationary pulley, a gear and rack means for moving the movable pulley through a. predetermined distance, a lever for operating said gear and rack means, and an automatic catch positively locking the lever at the extreme points of said distance.

7. In a portable polishing machine, a stationary rotatable pulley, a movable rotatable pulley, means for rotating said stationary pulley, a stationary guiding block between'said pulleys having a bore, a plunger having one end thereof slidable in said bore and its oppositeend carrying the movablepuiley, a spring arranged in said bore to act on said plunger and to urge the movable pulley away from the stationary pulley, an endless belt over said pulleys adapted to be depressed when applied to convex surfaces toward the line connecting the centers of said pulleys, a flanged belt retaining pulley arranged between said stationary and movable pulleys and engaging the idling portion of the belt for preventing throwing of the belt oi! the pulleys by the side thrust of curved surfaces, a rack formed on said plunger and an axiallystationary rotatable gear cooperating with said rack for moving the movable puiley through a predetermined distance, a

lever for operating said gear, and an automatic catch positively locking the lever 'at the extreme points of said distance, thereby permitting removal'of the belt as well as preventing the working portion of the belt from coming in contact with the belt retaining pulley.

r J. PAI'IISON. WILLIAM K.- BARTON. 

